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FHWA MSAT Study - US 95 Settlement Agreement June 2007 Annual Progress Report

In June 2005, the Federal Highway Administration (FHWA), the Nevada Department of Transportation (NDOT), and the Sierra Club settled a lawsuit filed to prevent the expansion of US 95 in Las Vegas, NV. In the settlement agreement, the FHWA agreed to conduct a study to characterize the emissions of mobile source air toxics (MSATs) and PM2.5 in relation to traffic and meteorological conditions, and measure the dispersion of the emissions from the roadway. This progress report, required by Part 1, Paragraph 5 of the settlement agreement, describes the progress over the past year on the FHWA's fulfillment of its obligations under the agreement.

Pooled Fund Program

After extensive outreach during 2005 and 2006, the FHWA determined that it would not be possible to obtain full funding from five states to conduct the near roadway studies, as originally envisioned in the settlement agreement. To leverage resources, a transportation pooled fund program was launched that secured smaller amounts of funding from interested parties. As a result of this effort, the FHWA was able to obtain funding commitments totaling $244,000 from Michigan, Kansas, Arizona, and New York. Nevada also contributed the $700,000 required of it by the settlement agreement. The pooled fund will provide an important supplement to the funds contributed by the FHWA and the Environmental Protection Agency (EPA) toward this effort.

Interagency Agreement

In addition to the pooled fund program, the FHWA entered into discussions with the EPA and the Department of Energy (DOE) to explore the possibility of a research consortium, with all partners contributing resources towards a shared research agenda. The EPA and the FHWA continued to explore the benefits of this approach. After considerable technical review, funding assessment, and agency coordination, the FHWA and the EPA executed an Interagency Agreement in June 2007 to conduct the studies. The EPA has agreed to provide $1.3 million in funding in addition to staff and contract support, while the FHWA will provide $1 million in funding, plus the amount obtained from the Nevada Department of Transportation and the pooled fund. These combined resources ($3.244 million) will allow studies to be conducted in Las Vegas, NV and Detroit, MI, as well as potentially a third site in Raleigh, NC, if funding permits. This consortium approach will allow the two agencies to pool resources and expertise to more effectively conduct this research effort.

Site Selection

Much of the focus of the FHWA's efforts on this project over the past year was on selecting the sites at which to conduct the studies. Based on the State of Michigan's interest in conducting a study and the Detroit metropolitan region's compatibility with the requirements of the Detailed Protocol, it was selected as the second site for the study. The FHWA has held a series of meetings with staff from the Michigan DOT and the FHWA Division Office. They have been particularly helpful in searching for potential sites in the Detroit area to site the monitors. This work is ongoing.

The concept of the North Carolina site was born from the FHWA-EPA consortium. The EPA had conducted a pilot study in the Raleigh, NC area, and given their proximity to the site, the FHWA and the EPA believe it is possible to conduct a third study at that site, provided that sufficient funding is available. This study would be conducted after the Las Vegas and the Detroit studies are completed.

Significant progress has been made in selecting a site in Las Vegas. The EPA staff spent considerable time developing potential sites in the city based on aerial photography, traffic data, meteorological data, and local information. These sites were discussed throughout the year and narrowed to a set of four potential sites. This effort was confounded by the construction of sound walls along the entire US 95 improvement section. Originally, it was assumed that the studies would be conducted at the OK Adcock school site, which was the focus of the settlement agreement. However, the FHWA and the EPA determined that, while their effect is not completely understood, it is likely that the presence of large sound walls would be too significant a factor. Given the research goals of the settlement agreement, it was decided to look for sites that would not have such confounding factors.

In May 2007, staff from the FHWA the EPA traveled to Las Vegas for a site visit. After visiting the four sites that had originally been selected as preferred candidates (including the OK Adcock school site), the staff determined that these sites had too many confounding factors. They were either below grade or had sound walls that would interfere with the monitoring. However, the site visit generated several other potential sites, with one in particular along I-15 near the Las Vegas Strip that seems particularly promising. The EPA and FHWA staff is currently working to obtain needed property access and consider other issues relevant to the siting of monitors at this location.

As the effort proceeds in Las Vegas, staff will continue efforts to make progress with the Detroit and Raleigh sites.


Over the past year, the FHWA has worked extensively with the EPA to form a partnership that may yield an additional study, to the benefit of all parties to the settlement agreement. Throughout the year, the FHWA has worked with the Sierra Club to ensure cooperation and communication. The FHWA believes that its collaborative and open approach to this process continues to have positive results, and looks forward to beginning monitoring at the Las Vegas site in the near future.

Updated: 7/6/2011
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